1. Field of the Invention
The present invention relates to an ink cartridge that is removably mounted on a carriage of an ink-jet recording apparatus including a recording head for performing recording of data such as characters or images by ejecting ink droplets from a nozzle opening, so as to supply ink to the recording head. More particularly, the present invention relates to an ink cartridge having an air-releasing valve and a vacuum-packaging product containing therein such ink cartridge.
2. Related Art
An ink cartridge for supplying ink to a recording head of an ink-jet recording apparatus includes: an ink chamber; an ink supply port that communicates with the ink chamber, to which an ink-supply needle can be inserted and which supplies the ink to the recording head through the ink-supply needle inserted therein; and an air passage for introducing ambient air into the ink chamber in accordance with reduction in the amount of the ink in the ink chamber with discharge of the ink via the ink supply port during consumption of ink.
However, since the ink chamber is in communication with the outside of the ink cartridge through the air passage, the ink in the ink chamber may leak into the outside of the ink cartridge through the air passage or change in quality, for example, become thick because of evaporation of solvent in the ink.